SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8a3762c711832ff1ace1935d18c97a868d874afd927457ac4509bbb9cceb859a' 
  AND token = 'NRcOBuvSYzhfg/ZWtxuzx1pvEVRCJYGx5cCoEHJtwdg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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