SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fd31bc7bb7836918f849a38f555ddcbf751575fafbfb030c63a22983e69a511' 
  AND token = 'CrQe8b9yPR4WTCRAhSXU+xVZS/AF+1mZz8paE4eVkCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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