SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a9163f1192f1d07ab96801cf432ce05fb1a15f7a1333b8e3defe7fe2391cee4' 
  AND token = '/bzFraI7YhAG8Ksw8koK3s6pcp+pyBuJfvp/KKSkoGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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