SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '714985f05747b9f9d1dfffe63746ac7ece2448b2ab726691419f7bcb9595f4d8' 
  AND token = 'b3AEkJBSa83lBNDcwFYBm/IxhYqhlolVehPPlFDzMXc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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