SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac0cc0cc921aaecc727700725c4466c63811e54f8a2ab237aaf063faa504e5cb' 
  AND token = 'b07jBeLHtJNNrpzK5kRSFIVqd6dLUA7vyaF5xwi1ITU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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