SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a510ca57c17c28081f3dc899843e7d31774f5dcbc54273514f11731b81399c2' 
  AND token = 'UGnH8aSfkvbwfS3htIjuDszIYqcOCKcU7bBgoESSsjY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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