SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0efc927f629ad341846adb4e2c6783d288620a27f2bb16c1b0c8c3d88b4dd13c' 
  AND token = 'Y0roOWNoXjzJ7qH7gfXW5R27chNXYz9xkgSQUSSMDlA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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