SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddae2cd05dddcda870ef0fe9b9c0575ffb03e1ccfcbac31af9404d1686b6dbff' 
  AND token = 'ZdWZpt0OjFInEKQD/H7mPQWJ+j1NmlOPd4qdayNZGGQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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