SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c13e68be45f89a0506895c4df9551879e514f202410b9ad9ff06bc4b4b92087' 
  AND token = 'N5gFPsVmuxSdKFBtBlPJqzgmUM8cAekEBhJj1d/5/Sg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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