SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd6cd3d3f2674d480fd6fe86bea72c948cffbfca04ab2beccd702bb9f3b651c6b' 
  AND token = 'rj2EVxadFkAl6iilr8OCX1OaIiWB6ZHnVdsEyikYn+Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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