SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7690683c9d8349fb196ae956312d78741c17d35b0fe1b63068421c089bdeb31f' 
  AND token = 'pWI0Pe6Zn2IpMj7cDscDXcEx5GDXznnlJSGMjKnr4cM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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