SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74c57b872283332106bf0861afe1f0db179f0b62c459daab2f8c95af0c17c07b' 
  AND token = 'PDd1S+GFYQYfuGNb9xvTNpvzkEUhOL0LoQ0HcDK3XAU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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