SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7b424977d583c104b443cda1213cead371e8ab52cda015b800b53ac837e6769a' 
  AND token = 'IoEMb+n5glfy6NLFkNGRsZ+6Cbjmki00dMPnse0r03k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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