SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49089cea2c92ef00923933e3a95d02333798f3833d82ce7411fc121839227f22' 
  AND token = 'M125xDW+Kf5wAAivrvgihctDoUNlhCYNAsJMSQKeBNA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00066

JSON explain

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