SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53f09156be0b2fa29ff46995bddec343f76d080026d88cf896725d49da1eb9e2' 
  AND token = 'YtXsJ/JLc/sGqaLKja30pilepFUYWid6LrFuNrI1gjo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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