SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f708e556cd69e796928361584f3e465d7ee721edb19d7fc4c620f695fe49dfb7' 
  AND token = 'he1oURa5qHA/2uYHyt/XiFnf3ZSSKgcIBdfbn2XqiaU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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