SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '0c975b699534017aa107d370004881eea2b9ff8d4162cfc69524fd885cc3dc30' 
  AND token = '1P7WMYlPL86HKZAPBaJ14zXp1LlBLskzfgq0BVrSDmk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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