SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '07356441fb702bbe1f99fc8e0aa6288989e9c97edf944703c017279beafa503d' 
  AND token = '5DJWCF0mDIukCNzVL89ASAG1uICcjDu8SBbli1y3fGI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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