SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9188debf31e1f62c7a466643e9e42bc016b22d70a9c279aa7c63196de1bc0281' 
  AND token = 'C8IL34AcVzRj4xaPSt4zhdpNzH3rYTbGwulaECq9zjs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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