SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '264a6e93bf5dad1ef9671779c145c0f769c082254b826e4c5258315613efb647' 
  AND token = 'cMjPkPyIYN5NGF/l8OgqVRyUJHQxaZx6AykqFV2cJhI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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