SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fca2a735b9084bae36d35a5ecc974bf8ef1718262a270be259749d6cc0f4c561' 
  AND token = 'V3AqpdYKwhLq09OagNMl5UdW0RJm3mq+Z0ahHgZcgoQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}