SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe07cd17913379923a79682bfdb6b41f4edded2254fe0f645af2609af85b0abb' 
  AND token = 'erJzANaVf1mxnCH3kObh6iIF/Qb6pDGg4ycs2KWxeQY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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