SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e63052d7c4a58796ae2e3221933d40233875f9c367f9d1d4964aab619785b0e' 
  AND token = 'BJB5+lQ8ur0PIQgS3cjusyhdujjmshlHnC6QE/gSluU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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