SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc84381307ba07da2a92d5fcf76e05a7d78d8fd41c3fa870ee6fd70513b4f7f2' 
  AND token = 'p4xw9Y2mVKDXtOki2FgdD+E43ceEzftS6dqB9C+gueI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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