Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c34aff4aaef8a7ebaa1398a85c6c7b3e6288e0334190781f20cc3d8ea9093d8f' 
  AND token = '86QEoVS8eN2/JmqrtP7aQX/DfTPxm6cIRe1DSimaVNk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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