SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5453711e7a598c7fa80bde8fa2125aab3e3a05f5ee01c473d754238c8dbc4c76' 
  AND token = '8Wk5Bv492AzThAAPUQvusdHeB2VkxKws8wmEsyLQTw8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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