SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9caf16634a27522dc9d71dc778297a72a635b93f4bbe21f562e1d31e019f36fd' 
  AND token = 'hZJMAx53ItMzGjdtG6D5cyM7esDO7s1c/fPCeZJ3GLs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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