SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '861a1bf130d409951e7364486dd3bbb9d8a8e9c3d0b578a413810a64d4448c05' 
  AND token = 'l1ltCK1UKcFLnrIPV50KUJERw/cLYUKOeKVLpaNnUnQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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