SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4113c8f2eac42704af6475f8adfad54ddf601b562ca28c94e9be5f1f805ab60' 
  AND token = 'XAemdtH8LJjNzITB40s7ucnkCZfoUSXRBeTin50LE68=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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