SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '552bfddd3f1aad89918065548050d5ea68ffaf67d5233985e53c14f947ed704e' 
  AND token = 'kzRNyGczRvwwu5QqyXOFR/ndPheKRcdV9XJsBlUrj9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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