SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f8bdef532a15b20da6522feace1a1c06aba561f1579d6bb7b8d80c46225bf73' 
  AND token = 'ARSzfxJcFjeMwXnE/mBPlH/x+J9PvqLluY1Fifd2Dgw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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