SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a86dc4080b84436b29703bd73147b9ac6ce0a665de9fe531f4f173d3614cf40' 
  AND token = 'mibozmExGLihdgE3b7T/HE3UyixbQal7U6OCxj3S+Tk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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