SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e87b7a655548ebe399ad103c34f7e80e8335cd8cad9c3701a9f75d60e1ed930' 
  AND token = 'tpjF1utYYpaW4La87tQXg33Kq8R5L6o6KKR9/K8qkjY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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