SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b5ef81a778ad0c760c6341ceef37cbae4c96cfa293822d4b9b84969b2533008' 
  AND token = 'BejVJrzxslpKfZcahHrCtb69pPhkAW7GmqMtwBbo5PI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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