SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a2bddd7edcc13956d6a115f7569137e84ddfc7b36742a506629b77da14a55fe' 
  AND token = '8178OijptEZZwERmNLoL2xGBZBmZFei06jXpNAJtcB0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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