SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2625d5521aca50c4729317e59629abc4de9a48f32992ea6e265b5369c051c77' 
  AND token = 'kxtrDR8XWKX55kAQmhS/CF8HDuuAHddfabOjBMRjvFc=' 
  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"
    }
  }
}