SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c65c4741e5760131e75647474f3581f67fdbb0191782d8bf7e10d7f36d19c9a' 
  AND token = 'DG85HhDW6sl8ev2qPXnBdznyHsiFV+mmsUgqZ5VRqpw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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