SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6abcd43786bede95ccd36af605d35a15a33525bc7426c45ffe3bef886b763fc8' 
  AND token = 'Lhok8E/ohaaQilKXvx1Q42EEVfnmlczTYITT8PBq1Xs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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