SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa234d77795e21362983add5ef63b9e392cb7b24f2f47ea059714724b06b281a' 
  AND token = 'IuiQzopR2oszU6DFn4AFgz0nS/Bpe0zxVfBiJXk2keo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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