SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a5c862eb7612dcf28c649e8ecc806e9dcd79363692d8047098b88e98a3f74004' 
  AND token = 'VMqNOKiEPzzHXaEGfxFz6eG1P6j3KiXMOX+U73fNMtg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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