SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e8add19eca10900ab96df69670bd1b43998bd59edfa1c1c128db5fb602c0140c' 
  AND token = '3iUFD20pLF+1VWBL/XUKKr27MbkggOUmT+hr02yvDmY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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