SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6b645182320b2eaa38724c0327261c3f399df133803afa44bd2997d67ca990d7' 
  AND token = 'hg6pONOfGGHaF455F2VBswqCctbUl1ISiCzCgJveX68=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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