SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'a960c1f83a2102d15787bbdf79bf86891c37f0e339987fb068e55840fa9cd8d8' 
  AND token = '2bLvXaifbI+ao5wp0PrE9nTO0Qr1tmK0BV3heEFRkdc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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