SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3fb411b7cfee169e1eac617833579987a3ab512e11252ad0f7986d476d612770' 
  AND token = 'ooblLJOwGWfnxn3/7HComRdBj87Q+fH8ChfRkSkgXe4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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