SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b679643e5f7f691d43943d1e525f0f626f8d7f840993d3c3aff6105063ff0e9' 
  AND token = 'wDD1B4AUB9nwhE0EWOGTJGwKAwyVE4FzKTOYfVNIRXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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