SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bfc6060721880f05a7c739969e76764bcd0ee1408d291c694dfef5aac591d830' 
  AND token = '+adJpuP2OQGBHL9mzN7Nm1Z71gyzo2INKr1PGpbSPkA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}