SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '8cacb8d9cadbac86d6f11517f8ff452d5627be6a731c829fd98933b9895f3426' 
  AND token = '1Akwk0UvVJ9bZvR2APefWbzCO/wOyYEv8FW8KMR9kfg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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