SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c0252eb9eb420f654e47b01642b65990a559c9f91afa312faeb557f91cb8799' 
  AND token = 'tGjF0eQ2W13UcezGaKo6srAQiWOL8ejSCNDzdulgzMU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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