SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80f0a5e92e6173057c3f2580f572107cbc3b49f01063f199d2d28156c3dda54f' 
  AND token = 'Gym3RSaj1qctgHYV6i+5Lvwlpfc7rMF37CZggJXb5c4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}