SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79d2bdb4af0c5b2beb8c688e4bf116249ccacb97951aa3ae5b1332e85c19638b' 
  AND token = 'qOMyOEKFxvq25kPmvC/YHEeYLxRJAU5oxigK1OIG6gE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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