SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13e3e77cb3a98d9231a9a4f91f64fcda62a7849483d6d5cc23bdb0b0f59bd5d6' 
  AND token = '9/2U6zcnocHE+godTNKvsNujOJmnmxehgjAOzqz9LZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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