SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67fbbffd5fe55e39b1b636eed5de411a3abed1efddc96547b448dda9a1cd4a7a' 
  AND token = 'q2cr42l8EmGF6nxaqTOK8tlQ23dTPpNgplaYYCaDMh8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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