SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '451471bc45827f54dc53e8b7cc7570960ca4faa78d296093fdc503c0b8beb372' 
  AND token = 'DoDuJIERgPlwJQY6cWzT1LPzxKsFswRcuapUNkzbcMs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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