SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5fee91f3fd29758675b8c136d87e914c4f20634eb85822be335ac1c87699ff0' 
  AND token = '++B0X2/ys5hLkM3gtVJrI5jD9+l96ihGCTJajOYdues=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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