SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e40f8c8a320c82ce12f31d688ea20104b7b388d5013664b22ba7a3f10ff38dc1' 
  AND token = 'l5GC1nGkmuFSXrqpwQftTK0OV+jr0ACH4DKp+kGHN3Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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