SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93590fb3713158ae9b6639bede98ce82323bd77e0d05952b6ca868a692cb991c' 
  AND token = 'VW+SMoO2mXxMz+LnJfS90RCXHbfSEGrwg1NJb8uxNzQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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