SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c682042892c61441bcab9b8ad1a89e8030458a93ddab254acb9543abed64b53' 
  AND token = 'kb6dWDm+tX0TNgSsWobb0Gp2nQkU+Ofsc+Mj+NJ2VUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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