SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c87f7a72b9a8888ba5c0562baab657bbc6d37a7d18b76144e2bd34016dff510e' 
  AND token = 'wW9C4UToh/lGOqTNnBAQwd0jmYo/nD/ANIwi9i4B1Dg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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