SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f080bcb60f2f6ceb41814a736cc37f23e70371691ecf11d73937d615acd6e91' 
  AND token = 'EHLCO2pfaElqIhNRYmsTPf8ugS4ROhsnpPF1+tUc67g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}