SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c37aa602941190642bbaf534185146cbdc8310c03a61f3bfe8246e1bfff172a1' 
  AND token = 'ZWdzEJ37XKZdzEz3A2EIV4CE/o8qEanWMn7WQCCI8ao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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