SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6d77392458990556ca2df496cd3d28ee63f4e5266db429292c765fde08c934b6' 
  AND token = 'W+8Kj2bg7BFepNdSVXjV7mBGIZuB9sxhxbY18iPK/Vw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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