SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40e5241808396381a30a0900632056a63419e9e473077a4cefb52b164c4092f6' 
  AND token = 'gkmFEE1NCjuJDVuSbglkBOHKhv12O81TdVoQjITc9dI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}