SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c2fcb3c76cc1cbd62a2e595528d4c15aabffd17bfcbeac482db15735d25e300' 
  AND token = 'K92jRIDFQQBlYNI5ICdwaD4O40HYO7ZWvBewWNBUdBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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