SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b882a4e3393b64f0be0693e6b30b80d9a74fa921f0929571dc01d538887026ff' 
  AND token = 'B2UVud33DeUSuqe7nSELayUqiVCPLDd+OyBPvCXLTlQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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