SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e9c575d8a42bed5ec79c7e6add2c341c1e80ee54085161f9414c710b8b1e5271' 
  AND token = 'dg2Ohz7S7zLVtkTaY5IMH6+/H14HuPKgGqp+u/y0/hE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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