SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63a0fe8395c29a63aafb7c34c9cec3a47e5b59210674f69cc405dd5f79e3a3e7' 
  AND token = 'UslugKTXIzmx+P7XOt2u+1lhFNxAyrkJYQVGlMbKfYY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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