SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2383c1b0e6fc58da28c134a3de7f957e62114e45321387228fcf3e01591a029' 
  AND token = 'YdDRRWQTh+/Y7nJHSiNlXg+tPQXqYYkB9VcBTwgsCYM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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