SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a20171e559962c5b61586a9fd3acd91f7be65abeb449525badc53c38cb996af6' 
  AND token = 'iqcLVfIo20BHGx+kG8O7r79NIBdW/djjBtScMxIjamM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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