SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f92220add000080fd5ea99502944873851ce93eb368815ec0b5201622998afb4' 
  AND token = '1D6O9TtTPIeuQbpsBky+vGtdzG8gky7YBOgtrep4zgI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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