SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0991998826f73d72d1c58d5641d67d56300f3535b8c181f6efe003d5627a604f' 
  AND token = 'UYpMVu1iAz+PDIXj3UnVDK7eluBNvxvW4EACniRxmWE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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