SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b6aa6a4fdfac1cb9df131925b07acd5d53096816aa0e06d445d9a90ca630fded' 
  AND token = 'QwLdV1pAdBn95fdc7i4j9IlwPII21KOJXaNbpIJWQHg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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