Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '21b2f17ffe32a095ff4fe741f2f0f7f7aa708a70db59fc5c64a3675a0e47ef58' 
  AND token = 'ZRnVZieX+GEeJGJccTwOxErjd/4/BuLfcZrjMbUvEjQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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