SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31538b0231da9ad0ed95108cac6f82d82dd41cee843f7b8675cc6c47860323fe' 
  AND token = 'i9JWWUM7oKxYcbpxiiDn6UEEvKh6hlkCuNiLLaFH5dA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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