SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c51b1613642aecd6402246e93031e8797881f0e9cb6cd6d0625b07f90b2111ee' 
  AND token = 'HY0yKnfjL7UilVXNgnnR7sFL/rux2w/MjuVXmOObgms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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