SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab3c3e8b9c829fff280698d1a275677785c16fcad2bee59725d7eb632f976bb3' 
  AND token = 'hojOhmvO0mJQZjZZaLHWs9+qAFs8/PUxWlZ8T9lE324=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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