SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '68f0d7ab3dce8578b657e4119fee062b51dc0d5e677ea2a8b772bb27bca8c1aa' 
  AND token = 'TE+mkU9KVGkY1tum8Y9M6u+M8ywWYziWxTBrZvhfQkg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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