SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de7902d40e1a531a3213d99e8b1bd24cc933f877356dcfd69671858cfe8bcf57' 
  AND token = 'IN2/1pTbVDZVKdpHJuLD2mAxH8IhjTeC6thhM4Z2QWs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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