SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e27f81479b6669661c6ef2fe9da8684c2a6d4991ef5ad8efe0783ae9e435b227' 
  AND token = 'MvcheW/Vq5KaulTPQzOqlmXcT4pSTN/2bkBV/wpZg2o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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