SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '783bfd0bb32ea8d3193f159eedebfebffece91ac7cf75e6d1b3002c2daf12089' 
  AND token = 'khu5SFyvclBd8rKenNe8i3FPDtgKW3MROzWDiR03Yos=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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