SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57b1f9716f2aac4872b78b0014a2bd915a5d369b341d55bf9b5b36e37b428831' 
  AND token = 'sTs4M/BNAGPYBsFCh9Y+/TMM8os+/EWp+tyieAA045o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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