SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a2e2b7dbb76effeae0d037371ca16b3c55650ba79ca888c38c47ccd015ebb41d' 
  AND token = 'UNba71VrYNXuvQ+YXYCBgQ0dKSprACIeJMIl2Qwryrw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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