SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ce3fbc133ba90e394d286453b3447fa9fdbed6644b3d504a68c89ee12c0705d' 
  AND token = 'JJ+LEeYM/MDQE5guxlWU9sHJ5yYwviWT2tzKzPNSiz8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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