SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4963c69c5be8236a710a02a876794bfba948f0d20c8dc13d82eb9d1eee627dd' 
  AND token = 'FpTiWHP1bOYGBm654CiRmhNQOpm70tWP0Y8aWkEX8x0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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