SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5611ebd023175d345600ef4c00d6df178e0c55efab97fc38734214ee094c5cf8' 
  AND token = 'UkBIOUC5AJaWbXf7LjvQxo6mZx9Yj7PPilaVNHve7O8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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