SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab150783970e9d17d19c18fc02d66297741aed8e27d12d756db80b7e2e793285' 
  AND token = 'avKGJcsgmLjD84evt8t+9jnB/Tj0+NCgqwUAzouZg2Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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