SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d61c31ea85b125d0f1ab24f18ae974c776a68c132cef3b3baf2a41a972c9bd1' 
  AND token = 'LIs2Kmpjrmq/PXqkGyJBiuvF14FbAfK6S4IuZzWeOe8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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