SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b86721032b4378ce8938f1ab1da9c01553f21c0595f27625af75b86fd20e8976' 
  AND token = 'EQlbwJboMXXSr7pc2vGpZo4ws6NmlWgTa8lzqaikCMs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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