SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f3730a39acab8cbb7598ddd7ff4f52960620ec3f6baa11f992b39072b7735e0' 
  AND token = 'jXhSZRcs4YDMOEnOxOp5YNQLmXEtKGjJOoQEzhdcHO8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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