SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0420677b75c17709f941a08c25143849ddc8bbcb36d4111d5fb29cf9d6e6b98b' 
  AND token = 'foyrQWkf0JoBqowJqYMheoNx9vxLcxwPn1Hk+MaebOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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