SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '01d93321b39b9f48b61dfc2062a47be66fa939fc46aea49f120ecdd5eab81fcc' 
  AND token = 'biveghrKRHbPKSFt7tyRVYZfXqVzL1jiXQJoBQO2iR8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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