SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c358220cf7022752e199d9bb7ca486af517f647a8bc5f6a66a843d09da28841a' 
  AND token = 'RpEjPcyohSq0PUlGMYrx2TCVBlMR716mNcj6wD7d8Pg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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