SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9458148b111c5b1243da18c4ba69560542b896f9470cca4aa99b7b82a6232136' 
  AND token = 'p4bqDayflQNmfCCoky70qY5m3Gr8pUfb8VNgWrE3Br4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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