SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc55f185b62b07f38d18a9aad722714484f75b8e43319b436c7bcd656e85369a' 
  AND token = 'nvFrg5h0dlcqY/P6snqo1kWI6jPQ4rZKPgthwgS6qQU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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