SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '236023f9b77d817249541135afaa4e296495ddd51c78b2e5781c3c835e2104d8' 
  AND token = '4+Sv6QY1hlIgSB5WgEjwCCCKIS58WxZx1BSXGKHBunI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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